Call-on signal control



Dec. 21, 1943. R. M|L s 2,337,204 l A CALL-N SIGNAL CONTROLI Filed July 17, 1942 2 Sheets-Sheet l Am C- [H3 HISTTURNK R. MILLS 2,337,204

CALL-ON SIGNAL CONTROL Filed J1. 11y 17, 1942 2 Sheets-Sheet 2 [NVENToR Habepzlz'llw.

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Patented Dec. 21, 1943 UNITED STATES PATENT OFFICE CALL-ON SIGNAL CONTROL Robert Mills, Forest Hills, N. Y., assignor to The Union Switch and Signal Company, Swissvale, Pa., a corporation of Pennsylvania ApplioatiOnJuly 17, 1942, Serial No. 451,255

8 Claims.

One of the objects of my invention is to provide improved means for controlling the call-on signals over the same line circuit that is provided for the control of the main signals.

Another object of the invention is to provide improved means for indicating response of the call-on signals over the same line circuit that is employed to indicate the condition of the main signals.

A further object of the invention is to provide improved call-on signal control apparatus which is adapted for use in connection with switch and signal control systems now in use.

Another object of the invention is to provide improved call-on signal control apparatus for use in connection with a switch and signal control system of the type shown in Letters Patent of the United States No. 2,106,990, granted February 1, 1938, to Harry C. Vantassel.

In practicing my invention I employ means responsive to the direct current supplied over the signal control circuit to determine which of the call-on signals is to be cleared and to also establish a pick-up circuit for a stick relay which is picked up on the supply of alternating current over the signal control circuit. This stick relay when picked up establishes a stick circuit to maintain itself picked up as long as direct current .is supplied over the signal control circuit, while it also establishes a circuit to clear the approf. priate one of the call-on signals.

` When a callon signal is cleared, direct current of one polarity or the other is supplied over the signal indication circuit to energize one of the 4indication relays at the control point, while at this time energy is also supplied to a slow pick-up relay which when it picks up cuts off the supply 'of direct current to the control circuit and supy apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the drawings,

Fig. 1 is a diagram illustrating one form of apparatus embodying my invention, and

Fig. 2 is a fragmentary diagram showing a modiiied form of apparatus which I may employ.

Similar reference characters refer to similar parts in both views.

In most instances in the drawings the relay contacts are shown directly under the relay winding, but in some cases in order to simplify the drawings, relay contacts are shown separated from the relay winding and where this is done the relay with which the contacts are associated is identified by appropriate reference characters placed directly over the relay contacts.

Referring to the drawings, there is shown therein a stretch of railroad track having a main track and a siding or diverging track which .is connected with the main track by means of a track switch W.

Trafllc may move in either direction over the main track, while the rails of the track stretch may be divided by insulated joints into track sections in the customary manner.

Movement of traic from left to right across the switch W is controlled by a signal RH which has an upper portion A which governs movement of traffic along the main track; a middle portion B which governs movement of traflic from the main track across the switch into the passing siding; and a lower o-r call-on portion C.

Movement of traine from right to left across the switch W on the main track is governed by a signal LHA which has an upper portion A, and a lower or call-on portion C. Similarly, movement of trafc from the branch track to the main track is governed by a signal LHB which has an upper portion A, and a lower or call-on portion C.

This invention is directed particularly to the control of the call-on signals and is not concerned with the control of the other signals or of the switch except insofar as the system of this invention is intended for use with a particular system for controlling the switch and the associated signals.

As pointed out above, the call-on signal control means provided by this invention is adapted for use particularly with the remote control system shown in Letters Patent of the United States No. 2,106,990 to Harry C. Vantassel.

In the system shown in the patent to Vantassel the switch and the signals are controlled by polarized relays WR and HR which are supplied with energy from a remote point over line wires, while the supply ci this energy is controlled by a two position switch control lever l,

and a three position signal control lever 2. The system of the Vantassel patent also includes means governed in accordance with the position of the switch and the condition of the signals for supplying energy to the line wires to provide at the control point indications of the position of the switch and the condition of the signals.

The manner in which the switch control relay WR controls the switch W is not a part of this invention and has been omitted in order to simplify the disclosure.

Similarly, the manner in which the signal control relay HR controls the main signals RHA, RHB, LHAA and LHBA is not a part. of this invention and has been omitted in order to simplify the disclosure.

The switch W has associated therewith a polarized indication relay WP to which energy of normal polarity is supplied when and only when the switch is in its normal position, and to whichv energy of reverse polarity is supplied when and only when the switch is in its reverse position.

The signals have associated therewith repeater relays RRG, LRG and RAG which are governed in accordance with the aspects displayed by the signals. The relay RRG is energized when and only when all three portions of the signal RH are displaying stop indications, while the relay RAG is energized when and only when the upper portion A of the signal RH displays its stop indication. The relay LRG is energized when and only when the main and call-on portions of both signals LHA and LHB are displaying their stop indications.

The improvement provided by this invention includes relays RHR, LHR and COSR which cooperate as hereinafter explained to control the call-on signals, while a slow pick-up relay COP is provided to control the supply of signal indication energy to the line circuit leading to the ofce. The equipment at the office includes signal indication relays RGPR, LGPR and COK, and a coding device CT.

As explained in the Vantassel patent, both the oilice and the station are provided with a source of direct current in the form of a battery having a negative terminal N, a positive terminal B, and a common or center terminal C, while the center terminals C of the two batteries are Connected together by a common wire.

The system of this invention makes use of alternating current which may be of any appropriate frequency and may be supplied from any suitable source. The terminal CX of this source is connected to terminal C of the batteries, and thus is connected over the common wire to both the orlice and station locations. The other terminal of the source of alternating current is designated BX.

A push button PB is located at the oce and is interposed in the wire Y and controls the supply of alternating current to this wire.

Operation of equipment to control the switch and the main signals The equipment is shown in the condition which it assumes when the switch control lever I is in its normal position and the signal control lever 2 is in its center or intermediate position.

As the switch control lever I is in its normal position, energy of norm-al polarity is supplied to the switch control relay WR over the circuit which is traced from terminal B of the ofce battery through the lever I, wire 3, back contact 4 j of relay HS, wire 5, back contact 6 of relay P;

wire X, back contact 9 of relay HR, wire I2, and winding of relay WR to terminal C. Accordingly, the neutral contacts of the relay are picked up, while the polar contacts of the relay occupy their normal positions so that the switch machine SM is controlled to maintain the switch in its normal position,

In addition, the contacts of relay WR establish the circuit to supply energy to the relay WK. This circuit is traced from terminal B over back contact I5 of relay HR, front neutral contact I6 and normal polar contact IS of relay WP, normal polar Contact 2i) and front neutral contact 2l of relay WR, wire Y, push button PB, back contact 26 of relay P, wire 2l, and winding of relay WK to terminal C. As energy is supplied to relay WK, its contact 29 is picked up, while the relay may have other contacts, not shown, which control indication lamps to indicate that the switch is in correspondence with the lever I,

If the switch lever I is moved to its reverse position, energy of reverse polarity is supplied to the relay WR and it causes the switch to move to its reverse position and when the switch is in this position, the contacts of relays WP and WR again establish the circuit to supply energy to relay WK.

If the operator wishes to clear a main signal to permit a train moving from left to right to cross the switch, he may do so by moving the signal control lever 2 to its right-hand position. On this movement of the lever the contact 2b completes a circuit for relay HS, so that this relay picks up and its contact 33 establishes a stick circuit to keep relay HS energized as long as the lever 2 remains in its right-hand position, while contact 34 of relay HS establishes a circuit for the slow pick-up relay P. In addition, when relay HS picks up, its contact 4 cuts off the supply of energy to the switch control relay WR, while the supply of energy to this relay is additionally interrupted when the contacts of relay P pickup. The neutral contacts of relay WR now release and prevent move- Y ment of the switch, while its contact 2I interrupts the supply of energy to wire Y and establishes connection from this wire to the winding of relay HR and also to the relays RHR and LHR. At this time contact 29 of relay WK releases but relay HS is maintained energized by current supplied over its stick circuit including its own front contact 33.

When the relay P picks up, its contact E connects wire X to wire 45, and thus to relays RGPR and LGPR, while its contact 25 connects wire Y to wire 35 and thus to contact 2a. The relay HR is now energized by current of reverse polarity which is supplied over the circuit which is traced from terminal C through the winding of relay HR, wire 31, back contact 2l of relay WR, wire Y, push button PB, front contact 26 of relay P, wire 35, and contact 2a, to terminal N. Accordingly, the neutral contacts of relay HR pick up, while the polar contacts of the relay move to their reverse position so that one of the signals RHA or RHB may be caused to display a proceed indication, the one depending upon the position of the switch.

If the signal control lever is moved to its lefthand position to clear a signal to permit a train moving from right to left to cross the switch, wire Y will be connected through contact 2a to terminal B of the source and energy of normal polarity is supplied to the relay HR over the circuit which is traced from terminal B through contact 2hr Wire 35,. front contact 26 of relay' P, push` button. PB, wire Y; back contact 2l oi relay wire 31,. and winding. of relay HR' toA terminal C.v |Ihe neutra-l contacts of relay HR 'therefore pick up, while the: relay polar contacts `move to their normal position so that one4 of the signals; LHAA or LHBA may beA causedztol display a; proceed indication, the one depending, onV the 1 position of the switch W.

When one of the main. signals displays. a. proceled' indication, oneqorthe other of the signal repeater relays releases; It' theV signal' RHA, or RHB displays a proceed indication, the relay RRG wilt release, while if: the signal'l RHA. displays. a proceed indication, the relay RAG will also release. If the signal LI-IAA or LI-IBA4 displays a proceed indication, the relay' LRG will release.

On releaseof the relay RRG whilev the relay LRG is pickedl up, connection. is established from terminal. B ot the. station. battery through back 'contact 5c' of reliay COP', back. contact 5I. of relay RRG., and: front' contact `5I of relay LRG to wire-N1.V lAt this time neutral' contact! 9 of relay HR isv picked? up and connects wire 44 to wire Xlso that energy is supplied over wire X, front contact 5 of relay P, wire: 45, asymmetric unit Ql,zback contact 54 of relay LGPR, and winding of' relay RGPR to terminal C.` Accordingly, the contacts ofv relaylRGPR pick up and establish the circuit for lamp RGEK which is traced from terminalV B through back contact 55 of relay CCK, front contact. 51 ot relay RGPR, and lamp RGWEK to terminal C.` The lamp RGEK, there- `fore'y isl lighted to: provvide: an indication that one of. the signals RHA or RHB is displaying a proceed indication.

' On release of the relay LRG its contact 52 establishes' connection from Wire 44 through back contact 53 of relay COP to the negative 4vterminally" of the station battery. At this time energyv is: supplied to relayv LGPR over the circuit which` is traced from terminal C through the winding: of relay LGPR, baclri contact 6D of relay RGPR, asymmetric unit Q2, wire 45, iront contact 6 of relay P, wire- X, front contact 9` oi. relay HR", wire. 134,v back contact 52 ot relay LRG, and back contact 53 of relay COP to terminal N. Accordingly, the' contacts of relay LGPR' pick up and establish the circuit' includ- Ving back contact 552 oi relay CCK and front contact 5| of relay-` LGPR to light the lamp LGEK' so that this lamp' indicates that one of thel signals LHAA or LHBA is displaying a pro- 'ceed indication. v

On subsequent restoration of the signal controllever 2! to its intermediate position the sup'- ply of energy to the relay HR is cut' andthe neutral contacts of this relay release to prevent 'the display of a proceed indication by the'main Isignals', While Contact 9 of rel-ay' HR cuts off the supply of' signal indication energy to wire X' and connectswire Xto relay' WR to-perrnit the switch fineanseffective at such times to control the" callon signals so that' the. appropriate one of. these will# display a proceed indication.

Control of call-on `signals When the. operatorv Wishes to clear one of the main signals governing movement of traffic from left to right, he moves the signal control lever 2 to its right-hand position, and, as explained above, energy of reverse polarity is supplied over Wire Y and wire 311 to signal control relay HR, while energy is supplied over a branch of wire 31- through` asymmetric unit` Q3, and back con.- tact 63 of' relay LHR. and vwinding of relay RHR so that. the contacts of relay RHR are picked up. Accordingly,.contact 64 oi' relay RHR interrupts the circuit of relay LHR and establishesrconnection from wire 31. to one input. terminal of rectifier 6.211 while contact S5 oi relay Rim interrupts one.` circuit for supplying energy to, the red lamp.- R` of call-on signal RHC and establishes a circuit to permit energy to be supplied to ther holding winding of relay COSR on picking up of the contacts of. that relay. At this time Contact. 61 of. relay RHR establishes a circuit to supply energy to the yellow lamp Y of the call-on Vsignal RHC on picking` up of the contacts of` relay vRAG remain energized and energy is not supplied over wires 44' and X to relay RGPR and the signal indication lamp RGEK remains dark so that) the operator knows that the main signals did, not respond to movement of the signal control lever.

If the operator now wishes to clear the call-on signal RHC, he maydo so by depressing the push button. PB. When this is done, the supply of direct current to the wire Y is cut ofi and terminal l BX of the sourcel of alternating current is connected. through front contact 28 of relay P to this wire.. The impulses of reverse polarity of this: energy aresupplied through the asymmetric unit Q3' to the winding of relay RHR and keep the contacts of thisy relay picked up, while the impulses, of' this eenrgy of normal polarity are supplied through asymmetric unit Q5, front contact EL of relay RHR, and rectifier Q4 to the pick-upwi-nding ot relay COSR so that the contacts of this relayl pick up and' its' Contact 12 completes the circuit including front contact S5 of relay RHR for supplying energy to the holding winding of relay COSR so that the contacts of this relay remain picked up after the push button is released and the supply of alternating current is cutoff. The relay RHR is snubbed by a rectifier sothat2 it is slow enough in releasing to remain picked upfV during the intervalsv in which the impulses of energy of normal polarity are supplied.

When the push button is released, the supply of alternating current over line wire Y is out ofi, While direct current of reverse polarity is again supplied thereto and keeps the relay' RHR energized so that its contact CA maintains the circuit l of the holding winding of relay COSR.

When the contacts of relay COSR pick up, its contact 6s interruptsthe circuit whichvit controls for supplying energy to the red lamp R ot' signal RHC and establishes the circuit including front contact 6l of relay RHR for supplying energy to the yellow lamp Y of signal RHC so that this lamp is lighted to permit a train to move across the switch.

When the signal RHC displays a proceed indication, the supply of energy to relay RRG is interrupted and the contacts of this relay release Yso that its contact l establishes the circuit including back contact 50 of relay COP for supplying energy of normal polarity over wires 44 and X to relay RGPR so that the contacts of this relay pick up.

In addition, on release of the relay RRG a cir- -cuit is completed for supplying energy to thesloW pick-up relay COP. This circuit is traced from Yterminal B through front contact 'l5 of relay COSR, front contact'l' of relay RAG, back contact 13 of relay RRG, and winding of relay COP to terminal C. The relay COP is of a type the contacts of which are slow in picking up so that they remain released subsequent to Yrelease of the contacts of relay RRG for a period Which is long enough to insure that the contacts of vrelay RGPR will become picked up by the direct current supplied thereto.

When the relay COP picks up, its contact 59 cuts off the supply of direct current to Wires 44 and X and connects the circuit of these wires to terminal BX of the source of alternating current. The impulses of this energy of normal polarity are supplied over the circuit traced above to relay RGPR andY keep the contacts of this n relay picked up, While the impulses of this energy of reverse polarity are supplied to the relay COK over the circuit which is traced from the terminal CX of the source of alternating current f through one leg of the rectifier Q6, Ythe winding of relay COK, another leg of the rectiiier Q6, front contact 6G of relay RGPR, asymmetric unit Q2, Wire 45, front contact 6 ofrelay P, wire X, front contact 9 of relay HR, Wire 4B, front contact 52 of relay LRG,' back contact 5| of relay RRG, and iront contact 59 of relay COP to terminal BX.

On the supply of energy to the relay COK its contacts pick up and contact l establishes a circuit to energize the coding device CT so that contact FS of the coding device is opened and closed at a predetermined rate, while contact 55 of relay COK interrupts the circuit for supplying steady energy to lamp RGEK and establishes a circuit including contact 'i9 of the coding device CT for supplying energy to the lamp RGEK so that this lamp provides a flashing indication which infor-ms the operator that the call-on signal RHC is displaying a proceed indication.

If the operator wishes to cancel the call-on signal, he may do so by moving the signal control lever 2 rto its intermediate position. This opens contact 2c and cuts oli the supply o-f direct current to relay HR and to relay RHR. On release of the contacts of relay RHR its contact 55 interrupts the circuit of the holding Winding oi' relay COSR so that its contacts release and its Contact 'l2 additionally interrupts the holding winding of relay COSR so that the relay will remain released until the push button PB is again lever 2 to its intermediate position 'contact 2b interrupts the circuit of relay HS so that lt releases and its contact 34 interrupts the circuit of relay P The relay P.als`o releases so that its contact 6 reestablishes the circuit for supplying energy to the switch control relay WR, its contact 26 prevents supply of direct current signal control energy to Wire Y and connects wire Y to relay WK, While contact 28 of relay P interrupts the alternating current supply circuit to thereby prevent supply of alternating current to the wire Y if the lJush button PB is depressedwhile the signal control lever is .in its intermediate position. L

On release or the relays COSR and RHR the circuit of the yellow lamp Y of signal RHC is interrupted and the circuit of the red lamp R of this signal is established.

On release of relay COSR its contact T5 interrupts the circuit of relay COP, while when the signal RHC displays its stop indication, relay RRG is again energized andits contact 13 additionally interrupts the circuit of the relay COP and its contact 5I interrupts connection from wire i4 to terminal B of the station battery.

The equipment operates in a similar manner to permit control of the call-on signals LI-IAC and LHBC. When the operator wishes to clear one of the main signals LHAA or LI-IBA, he moves the signal control lever 2 to its left-hand position. When the signal control lever is in this position, contact 2b establishes a circuit for relay HS so that it picks up and establishes a sti .i circuit for itself, while it also establishes the circuit for relay P so that the signal lever contact 2a causes direct current of normal polarity to be supplied over wire Y to relay HR and over a branch of wire 37, asymmetric unit Q5, and back contact 64 of relay RHR to the winding of relay LHR and the contacts of this relay pick up.

When the relay LHR picks up, its contact 63 interrupts the circuit of relay RHR and establislies connection from wire 3'! to one input terminal of rectiiier Q4, while contact 'Ill of relay LHR establishes the circuit to supply energy to the holding Winding of relay COSR on picking up of the contacts of that relay. Contact 10, when picked up, interrupts one circuit for supplying energy to the red lamp R of signal LHAC, but this lamp is maintained lighted at this time by energy supplied over the circuit established by back contact I5 of relay COSR.

In addition, when the lcontacts of relay LHR pick up, contact 8| interrupts a circuit for supplying energy to the red lamp R of signal LHBC, but this lamp is maintained lighted by energy supplied over the circuit including back contact 32 of relay COSR.

`A polar contact 84 of the switch indication relay WP also controls circuits for supplying energy to the red lamps of the signals LHBC and LHAC so that the red lamp of the signal LHBC is maintained lighted as long as the switch is in its normal position, and the red lamp R of signal LHAC is maintained lighted as long as the switch is in its reverse position.

When the contacts of relay LHR pick up, its contact 85 is closed to permit energy to be supplied to the yellow lamp Y of signal LHBC or LHAC, depending on the position of the switch.

If the main signals fail to provide proceed indications after the signal control lever 2 is moved to its left-hand position, the signal repeater relay LRG Will remain energized and energy Will not be supplied to relay LGPR, and the lamp will remain dark so the operator will know that the main signals remain at stop.

If the operator now depresses the push button PB, the supply of direct current to wire Y is cut off and this wire is connected through front contact 28 of relay P to terminal BX of the source of alternating current. The impulses of this energy of normal polarity are supplied to the relay LHR over the circuit previously traced for this relay, while the impulses of this energy of reverse polarity are supplied through the rectifier Q4 to the pick-up winding of relay COSR over the circuit which includes front contact 63 of.

relay LHR and asymmetric unit Q3.

The relay COSR now picks up and its contact 12 Acompletes the circuit of the holding winding of relay COSR so that the contacts oi the relay remain picked .up after the operator releases the push button. AWhen the operator releases the push button, the supply of alternating current is vrcut ofi While direct currentrof normal polarity is again supplied over wire Y to relays HR and LHR so that the contacts of relay LHR remain picked up and maintain the circuit of the holding winding of relay COSR. y As the contacts of relays COSR and LHR are picked up, contact 82 of relay COSR and contact 8| of relay LHR interrupt the circuits which they control for supplying energy to the red lamp R of signal LHBC, but as the switch is in its .normal position, contact 84 of relay WP maintains the supply of energy to the red lamp of signal LHBC so this lamp continues to be lighted.

At this time contact 'E0 of relay LHR and contact l5 of relay COSR interrupt the circuits which they control for supplying energy to the red lamp R of signal LHAC and this light is extinguished, while the yellow light Y of signal LHAC is lighted by energy supplied over the circuit which is traced from terminal B through front conta-ct 59 of relay COSR, front contact 85 of relay LHR, iront neutral contact 8l and normal polar contact 88 of relay WP, and yellow lamp Y of signal LHAC to terminal C. The call-on signal LHAC, therefore, provides a proceed indication to permit a train on the main 'track to advance across the switch. 4

jIf when the operator pressed the push button to pick up the relay COSR the switch had been in the reverse position, contact 84 of relay WP would have maintained the supply of energy to the red lamp R of signal LHAC, while contact 88 of relay WP would have caused the yellow light of signal LHBC to be lighted so that this signal would providel a proceed indication to permit a train on the branch track to cross the switch.

AWhen either of the signals LHAC or LHBC displays a proceed indication, signal repeater relay LRG releases and its contact 52 establishes connection from wire 44 through back contact 58 of relay COP to terminal N of the station battery so that energy of reverse polarity is supplied to relay LGPR over the circuit which is traced from terminal C through the winding of relay LGPR, back contact 58 of relay RGPR, asymmetric unit Q2,`wire 45, front contact 6 of relay P, wire X, front contact 9 of relay HR, wire 4d, back vcontact 52 of relay LRG, and back .contact 58 'of relay COP to terminal C. Accordingly, the contacts of relay LGPR pick up so that contact 54. interrupts the circuit of relay RGPR `and establislies connection from wire 45 to an input termnal of rectifier Q6, while contact '6l establishes the circuit of lamp LGEK.

On release of relay LRG energy is supplied to slow pick-up relay COP over the circuit which is traced from terminal B through front contact 15 of relay COSR, front contact 1E of relay RAG,

back contact 89 of relay LRG, and winding of` relay COP to terminal C. After a time interval long enough to insure that the contacts of relay LGPR have picked up, the contacts of relay COP pick up and its contact 58 interrupts connection from wire 44 to terminal N and connects this wire to terminal BX of the source of alternating current.

The impulses of alternating current energy of reverse polarity supplied over wire 44 and wire X maintain the relay LGPR picked up, while the impulses ci this energy of normal polarity are supplied through asymmetric unit QI, iront con-` tact 54 ci relay LGPR, and rectilier QB to the winding ot relay COK. This relay now picks up andits contact 18 establishes the circuit of the coding device CT, while contact 55 cuts oi the supply of steady energy to the lamp LGEK and establishes the circuit including contact 'i9 of the coding device CT for supplying energy to the lamp LGEK so this lamp provides a flashing indication to advise the operator that one of the call-on signals is displaying a proceed indication.

On subsequent movement of the signal control lever 2 to its intermediate `position contact 2a cuts off the supply of direct current of normal polarity to wire Y, and thus to relays HR. and LHR so that relay LHR releases and its contact l0 interrupts the circuit of `the holding winding of relay CSSR and this relay releases. In addition, on release of .relay LHR its contact interrupts the circuit for supplying venergy to the yellow lamp of one of the call-on signals, while contacts l0 and 8l of relay LHR establish circuits for supplying energy to the red lamps of signals LHAC and LHBC, respectively,.so that both of these signals display stop indications.

When relay COSR releases, its contact 15 interrupts the circuit of .relay COP, while when the signals LHAC and LHBC both display stop indications, relay LRG is again energized and its contact 89 additionally `interrupts the circuit of relay COP, while .its contact 52 prevents the suppl-y of direct current to wire 44 on release of the contacts of relay .COP` As the supply of both alternating vand direct current .to wires M :and X is cut on, relays LGPR and COK release and interrupt the circuits of the lamp LGEK and of the coding device CT.

Construction .and operation of modification `shown in Fig. 2

In Fig. 2 of the drawings there is shown a modied form of apparatus which I may employ to control the callon signals. Except as hereinafter pointed `out in Adetail the system of Fig. 2 is the same in construction and operation as that shown in Fig. 1 and `only those portions of the system 'are shown in Fig. 2 as are essential to the' understanding of this modincation.

' The `system shown in Fig. l2 employs a transformer TA, 4'the secondary winding of which is connected in series with the wire Y and is of relatively low resistance so that it Adoes not substantially reduce the supply of direct current over this wire. One terminal of the primary winding ofthe transformer TA 'is `connected to common wire C 'and thus to :terminal -CX of the source of alternating current, while the other terminal of this winding is `connected tothe movable contact of the `push button PB. 'The movable contact of the 'push button is biased to a' position in which it short circuits the transformer primary Winding and thus prevents inductive surges in the circuit ofwi're Yon changes in the polarity of the direct current supplied thereto. When the push button is depressed, its contact establishes connection with terminal BX of the source of alternating current if contact 28 of relay P is picked up.

The pick-up winding of the relay COSR is supplied with energy over wire Y through the transformer TB and a rectier Q4, while connection from Wire 3l to the primary winding of the transformer is controlled by neutral contact 99 of relay HR. A condenser K is included in yseries with the circuit of the primary winding of the transformer TB to prevent ow of direct current in this winding. The circuit of the holding winding of relay COSR is controlled by contact 'I2 of the relay and by contact 92 of relay HR.

The relays COSR and HR cooperate as hereinafter explained to control the call-on signals, while the relay HR operates as explained in connection with the system shown in Fig. 1 to control the main signals.

When the operator desires to clear a signal to permit a train moving from left to right to proceed across the switch, he moves the signal control lever 2 to its right-hand position and causes relay P to be energized as explained above, while direct current of reverse polarity is supplied over line wire Y and back contact 2| of relay WR to the relay HR. Accordingly, the neutral contacts of relay HR pick up and its polar contacts move to .their reverse positions to establish a circuit, not shown, to permit signal RHA or RHB to clear. If traino or other conditions in the vicinity of the switch are such that these signals remain at stop, no indication will be returned to the oiilce. The operator may now Wish to clear the call-on signal RHC and to do so he presses the push button PB.

When the push button PB is depressed, alternating current is supplied to the primary winding of transformer TA and energy is induced in the transformer secondary from which energy is supplied over wire Y, back contact 2l of relay WR, wire 3l, front contact QG of relay HR, and condenser K to the primary winding of the transformer TB. The other terminals of the transformer windings are connected together through the common wire and one-half of the ofce battery. At this time alternating current is supplied to the winding of relay HR, but the impedance of this winding is so high that flow of alternating current therein is substantially prevented. In addition, at this time the supply of direct current to the winding of relay HR is maintained so the neutral contacts of this relay are maintained picked up.

On the supply of alternating current to the primary winding of transformer TB energy is supplied from the transformer secondary winding through the rectifier Q to the pick-up winding of relay COSR and the contacts of this relay pick up so that contact 'l2 completes the circuit including iront contact 92 of relay HR for supplying energy to the holding winding of relay COSR. Accordingly, the contacts of relay COSR will thereafter remain picked up as long as relay HR is energized.

On subsequent release of the push button PB the supply of current over the wire Y to the pickup winding of relay COSR is cut off, but the contacts of the relay are maintained picked up by the relay holding winding. The circuit of the relay holding winding is maintained by contact 92 ofrelay vHR as direct current continues to besupplied to this relay as long as the signal control lever remains in its right-hand position.

for supplying energy to the red lamp R of signal RHC, while polarl contact 93 of relay HR interrupts the circuit which it controls for supplying energy to this lamp so that-it is extinguished. When contact G9 of relay COSR is picked up, it establishes a circuit to supply energy to the yellow lamp Y of signal RHC. This circuit is traced from terminal B through front contact 69 of relay COSR, front neutral contact 94 and reverse polar contact 95 of relay HR, and lamp Y- to terminal C. Accordingly, the yellow lamp Y of signal RHC is lighted and this signal authorizes a train to advance across the switch.

At this time reverse polar contact 93 of relay HR maintains the supply of energy to the red lamp R of signal LHAC, while reverse polar contact 9S of relay HR maintains the supply of energy to the red lamp R of signal LHBC so these signals both display stop indications after` relayCOSR is picked up. Contact 84 of relay WP also establishes a circuit to supply energy to one or the other of these signal lamps depending on the position of the switch.

In addition, when the contacts of relay COSR are picked up, contact 'l5 establishes the circuit to supply energy to relay COP, as explained in connection with the system shown in Fig. l, so that an indication is provided at the olce that the call-on signal RHC is displaying a proceed indication.

When the operator wishes to cancel the call-on signal, he may do so by returning the signal control lever t0 its intermediate position. This cuts off the supply of direct current to relay HR and the contacts of relay HR release so that contact 92 interrupts the circuit of the holding winding of relay COSR and the contacts of relay COSR release. The yellow lamp Y of signal RHC is now extinguished and the red lamp of the signal is again lighted, while the signal indication energy transmitted to the office is cut off.

rIhe equipment operates in a similar manner to control the call-on signals LHAC and LHBC. When the operator wishes to clear a signal to permit a train moving from right to left to cross theswitch, he moves the switch control lever 2 to its left-hand position and causes a circuit for relay P to be established so that its contacts pick up with the result that direct current of normal polarity is supplied over wire Y to relay HR. Accordingly, the neutral contacts of relay HR pick up while the polar contacts of the relay move to their left-hand or normal positions so that a circuit is established to permit clearing of one of the signals LHA or LHB. If traic or other conditions are such that these signals both remain at stop, no indication will be sent to the oflice and the operator may wish to clear one of the call-on signals.

If the operator now depresses the push button PB, alternating current energy will be supplied over Wire Y and back contact 2| of relay WR to transformer TB, and therefrom through the rectifer Q4 to the pick-up winding of relay COSR. The contacts of relay COSR now pick up and contact 12 completes the circuit for the relayA holding winding so that the relay contacts remain picked up after the operator releases the push button and the supply of alternating current is cut off.

acer-,co4-

flWnen nie contacts .ofr'eiay cosa pick up,"

Contact '69 interrupts the circuitwhicn it 'ccntrols 4for supplying energy to the red lamp Roi signal RHC, but energy is supplied to this lamp over the circuit established by normalv polar contact 93 of relay HR and signal RHC" continues to provide 'its stop indication.

When contact 69 of relay COSR is picked up, it establishes a circuit controlled by contacts of the signal control relay HR and by contacts of the -switch indication relay WP for supplying energy to the yellow lamp Y of signal LHAC or LHBC depending on the position of the switch W. `If the switch is in its normal position, energy supplied to the lamp Y of signal LHAC over the circuit which iis `traced from terminal B through ifront contact 69 of relay COSE, front neutral contact 94 and normal polar Contact 95 of relay HR, front neutral contact 8T and normal polar contact 8S of relay WP, and yellow lamp Y of fsignal LHAC to terminal C.

lIf `the switch is in Vits reverse position, the yellow lamp of signal vLI-IBC `is lighted instead of `the yellow lamp of signal `LHAC. The circuit for the lamp of signal LHBC is the same as that fo'r the yellow lamp of-signal LHAC except that Aift includes reverse polar contact 88 of relay WP instead of the normal polar contact.

At this time polar contact` 84 of relay WP establishes a circuit to light the red lamp of the one of the signals LHAC and LHBC which does not have its yellow lamp lighted, while contacts 82 and 15 of relay COSR interrupt the circuits i which they control for supplying energy to the red lamps 'of `signals LHAC and LHBC. In addition, contact 'l5 of relay COSR establishes the circuit to supply energy to Vrelay COP so that alternating current indication energy is supplied tothe office to notify the operator that one of the call-on `signals is displaying a proceed indication. i

When the operator wishes to cancel the call-on signal, he returns the signal control lever to its intermediate position. This deenergizes the relay P and cuts off the supply of direct current of normal polarity over the wire Y to relay HR and its neutral contacts release so thatl contact 92 interrupts the circuit of the holding winding of relay COSR. As the relays COSR and HR are released, all of the call-on signals display stop indications, while the 'circuit of the relay COP is interrupted so that alternating current signal indication energy is no longer supplied to the oiiice.

From the foregoing, it will be seen that the modiiication shown in Fig. 2, like that shown in Fig. 1, provides means to control the call-on signals by supplying alternating current over the same wire that direct current of one polarity or the other is supplied to control the main signals. It will be seen also that the systems of this invention provide means to transmit an indication of the response of the call-on signals over the same Wire that indications of the condition o main signals are transmitted.

. While the call-on signal control means provided by this invention is arranged particularly for use with the remote control system shown in the patent to Vantassel, the means provided by this invention is not limited to use in this manner but may be employed in other situations. Although I have herein shown and described only two forms of signal control apparatus embodying my invention, it is understood that various changes and modiications may be made therein within fthe scope `of the appended claims Without departing from the spirit fand 'scope o'f my invention. 4

Having lthus described 'my invention, what I claim is:

14. Infcombinatiom a section vof -railroad track, a rst main signal and a rst call-on signal governing .movement of traic in one direction through said track section, a second main .signal and `a second call-on signal governing movement of traiiic in the other direction through said track section, `a polarized signal control relay which when energized with current of normal polarity may lcause the rst main signal to provide arproceed indication and which when energized by current of reverse lpolarity may cause the `secon-d main signal to provide a proceed indication, a line circuit for supplying energy 'to said polarized relay, -means for at times supplying energy of normal polarity and at other times supplying 'energy of reverse lpolarity to `said line circuit, means lfor also supplying alternating current to `said line circ-uit, -a Ylrst and Va second auxiliary relay, a circuit including a lback contact of the second auxiliary relay andan asymmetric uni-t poled to permit ow of 'energy -of normal polarity for supplying energy from saidv line circuit to said first auxiliary relay, a circuit including a back Contact of the rst Aauxiliary relay vand an asymmetric unit poled to permit flow of energy `of reverse polar-ity for `supplying energy 'from' said line circuit to said second auxiliary relay, 4a stick relay, each auxiliary -relay being effective when picked up to establish a circuit for supplying from the line circuit to the stick relay through a rectier energy impulses of the polarity other than that of the impulses supplied to such auxiliary relay, said stick relay being eifective when picked up providing either of said auxiliary relays is picked up to establish a holding circuit to maintain it self picked up, a circuit controlled by said stick relay and said first auxiliary relay for causing the rst call-on signal to provide Va proceed vindication, and a circuit controlled by said stick relay and said second auxiliary relay for causing the second call-cn signal to provide a proceed indication.

2. In a remote control system, in combination, a control cnice, a rst and a second line circuit connecting the control oce with a remote station, a ilrst and `a second traffic controlling device at the remote station, means at the ofce for at times supplying direct current energy to said first line circuit, means at the oice for at times supplying alternating current energy to said first line circuit, a rst relay at the station responsive to direct current supplied over said first line circuit and controlling said first traiiic controlling device, a second relay at the station responsiveto alternating current supplied over said first line circuit and controlling said second traino controlling device, means governed in accordance with the condition of the rst trafc controlling device for supplying direct current to said second line circuit, means governed in accordance with the condition of the second trafo controlling device for supplying alternating current to said second line circuit, and indication means at the office selectively responsive to direct and alternating current supplied over said second line circuit.

3. In a remote control system, in combination, a control cnice, a iirst and a second line circuit connecting the control olce with -a remote station, a rst and a second traflic controlling device at the remote station, means at the office for at times supplying direct current energy to said first line circuit, means at the oii'ice for at times supplying alternating current energy to said first line circuit, a first relay at the statio-n responsive to direct current supplied over said iirst line circuit and controlling said first traffic controlling device, a second relay at the station responsive to alternating current supplied over said iirst line circuit and controlling said second traiiic controlling device, means governed in accordance with the condition of the first traflic controlling device for supplying direct current to said second line circuit, means governed in accordance with the condition of the second traffic controlling device for supplying alternating current to said second line circuit, an indication lamp at the omce, means at the oiiice responsive to direct current energy supplied over said second line circuit for establishing a circuit to steadily energize said lamp, and other means at the oiiice responsive to alternating current energy supplied over said second lline circuit for establishing a circuit to intermittently energize said lamp.

`4. In a remote control system, in combination, a control cnice, a iirst and a second line circuit connecting the control oice with a remote station, a section of railroad track, a iirst main signal and a first call-on signal governing movement of traffic in one ldirection through said track section, a second main signal and a second call-on signal governing movement of traiiic in the other direction through said track section, a polarized relay at the station energized over said rst line circuit and which when energized with current of normal polarity may cause the first main signal to provide a proceed indication and which when energized with current of reverse polarity may cause the second main signal to provide a proceed indication, means at the.

ofiice for at times supplying direct current of normal polarity and at other times supplying direct current of reverse polarity to said first line circuit, means at the oiiice for also supplying alternating current to said rst line circuit, a call-on control relay at the station responsive to alternating current supplied over said rst line circuit for causing the first or the second call-on signal to provide a proceed indication according as direct current oi^ normal or reverse polarity is supplied to said first line circuit, a rst repeater relay which is deenergized when either the rst main signal or the rst call-on signal displays a proceed indication, a second repeater relay which is deenergized when either the second main signal or the second call-on signal displays a proceed indication, a slow pick-up relay, means elective on release of either the first or the second repeater relay when the call-on control relay is energized for applying energy to said slow pick-up relay, means including back contacts of said slow pick-up relay and of said first repeater relay for supplying direct current of normal polarity to said second line circuit, means including back contacts of the slow pick-up relay and of the second repeater relay for supplying direct current of reverse polarity to said second line circuit, means including a front contact of said slow pick-up relay for supplying alternating current to said second line circuit, a first, a second and a third indication relay at the control ofce energized over said second line circuit, the rst indication relay being responsive only to energy of normal polarity, the second indication relay being responsive only to energy of the reversev polarity, the third indication relay being responsive to alternating current energy, each of said indication relays being effective When energized to provide a distinctive indication at the control office.

5. In a remote control system, in combination, a control office, a rst and a second line circuit connecting the control oiiice with a remote station, a section of railroad track, a first main signal and a first call-on signal governing move ment of traic in one direction through said track section, a second main signal and a second call-on signal governing movement of traflic in the other direction through said track section, a polarized relay at the station energized over said rst line circuit and Which when energized with current of normal polarity may cause the first main signal to provide a proceed indication and which when energized with current of reverse polarity may cause the second main'signal to provide a proceed indication, means at the oilice for at times supplying direct current of normal polarity and at other times supplying direct current of reverse polarity to said first line circuit, means at the oflice for also supplying alternating current to said rst line circuit, a call-on control relay at the station responsive to alternating current supplied over said rst line circuit for causing the rst or the second call-on signal to provide a proceed indication according as direct current of normal or reverse polarity is supplied to said rst line circuit, a first repeater relay which is deenergized when either the rst main signal or the first call-on signal displays a proceed indication, a second repeater relay which is deenergized when either the second main signal or the second call-on signal displays a proceed indication, a slow pick-up relay, means effective on release of either the iirst or the second repeater relay when the call-on control relay is energized for supplying energy to said slow pickup relay, means including back contacts of said slow pick-up relay and of said first repeater relay for supplying direct current of normal polarity to said second line circuit, means including back contacts of the slow pick-up relay and of the second repeater relay for supplying direct current of reverse polarity to said second line circuit, means including a front contact of said slow pick-up relay for supplying alternating current to said second line circuit, a first, a second and a third indication relay at the control oflice, a circuit including a back contact of the second indication relay and an asymmetric unit poled to permit flow of energy of normal polarity for supplying energy from said second line circuit to the first indication relay, a circuit including a back contact of the first indication relay and an asymmetric unit poled to permit iiow of energy of reverse polarity for supplying energy from said second line circuit to the second indication relay, the first and second indication relays each being effective when picked up to establish a circuit to supply energy from said second line circuit through a rectifier to the third indication relay, means controlled by a circuit including a front contact of the fiist indication relay and a back contact of the third indication relay for providing a first indication, means controlled by a circuit including a front contact of the second indication relay and a back contact of the third indication relay for providing a second indication, means controlled by front contacts of the first and third indication relays for providing a third indication, and means controlled by front contacts of the second and third indication relays for providing a fourth indication.

6. In combination, a section of railroad track, a rst main signal and a rst call-on signal governing movement of traiiic in one direction through said track section, a second main signal and a second call-on signal governing movement of trai-hc in the other direction through said track section, a polarized signal control relay which when energized with current of normal polarity may cause the iirst main signal to provide a proceed indication and which when energized with current of reverse polarity may cause the second main signal to provide a proceed indication, a line circuit for supplying energy to said polarized relay, means for at times supplying energy of normal polarity and at other times supplying energy of reverse polarity to said line circuit, means for at times also supplying alternating current to said line circuit, a stick relay, a transformer, means including a front neutral contact of said polar relay for applying energy from said line circuit to the primary Winding of said transformer, means for supplying energy from the transformer secondary Winding through a rectifier to said stick relay, a holding circuit including a front contact of said stick relay and a front neutral contact of said polar relay for also supplying energy to said stick relay, and circuits controlled by said stick relay and by polar contacts of said polar relay for causing said callon signals to provide proceed indications.

'7. In a remote control system, in combination, a control office, a rst main signal and a rst call-on signal at a remote station and controlling movement of traic in one direction through a stretch of railroad track, a second main signal and a second call-on signal at the remote station and controlling movement of traic in the other direction through said track stretch, a line circuit connecting the control office with the remote station, a supply transformer at the control oice having its secondary winding included in series With said line circuit, a manually operable switch biased to a position in which it short circuits the primary Winding of said supply trans former and movable therefrom to a position in which it causes alternating current to be supplied to said primary Winding, means for at times supplying direct current of normal polarity and atother times supplying direct current of reverse polarity to said line circuit, a polarized signal control relay at the remote station energized over said line circuit and which when energized with current of normal polarity may cause the first main signal to provide a proceed indication and which When energized with current of reverse polarity may cause the second main signal to provide a proceed indication, a stick relay, means effective only when alternating current is supplied to said line circuit to supply energy from said line circuit to said stick relay, a holding circuit for said stick relay including its own front contact and a front contact of a relay responsive to direct current supplied over said line circuit, and means governed by said stick relay and by the polarity of the direct current supplied over said line circuit for controlling said call-on signals.

8. In a remote control system, in combination, a control oice, a first main signal and a rst call-on signal at a remote station and controlling movement of tramo in one direction through a stretch of railroad track, a second main signal and a second call-on signal at the remote station and controlling movement of trafc in the other direction through said track stretch, a line circuit connecting the control ofce with the remote station, means for at times supplying direct current of normal polarity and at other times supplying direct current of reverse polarity to said line circuit, a rst transformer at the control oiice having its secondary winding connected in series with said line circuit, a manually operable switch biased to a position in which it short circuits the primary winding of said first transformer and movable to a position in which it causes alternating current to be supplied to said primary Winding, a polarized signal control relay at the remote station energized over said line circuit and which when energized With current of normal polarity may cause the rst main signal to provide a proceed indication and Which when energized with current of reverse polarity may cause the second main signal to provide a proceed indication, a stick relay, a second transformer at the remote station, means governed by a relay responsive to direct current supplied over said line circuit for supplying energy from said line circuit through said second transformer to said stick relay, a holding circuit for said stick relay including a front contact of said stick relay and a front contact of a relay responsive to direct current supplied over said line circuit, and means governed by said stick relay and by means responsive to the polarity of the direct current supplied over said line circuit and controlling said call-on signals.

ROBERT MILLS. 

